Performing outdoor activities in cold weather can be uncomfortable. For athletes who participate in outdoor activities in cold weather, it can be a challenge to dress appropriately. To be comfortable, the athlete must maintain a comfortable overall body temperature by staying warm enough in the cold temperatures without getting too warm while body temperatures are elevated due to physical activity.
Maintaining a comfortable body temperature can be especially difficult for runners whose body temperatures often vary significantly during the course of a workout. At the beginning of a run in cold weather, a runner will feel cold and will desire warmer clothing. However, within half an hour of constant physical exertion, the heart rate and metabolism of the runner will increase significantly, thus the runner's body temperature will also increase significantly. Once the runner warms up, he will require less clothing to maintain a comfortable body temperature. If the runner stops running for a substantial period of time during the course of the run to stretch or wait for traffic, the runner's body temperature may cool down again, leading to a repeat of the process described above.
One way that a runner can deal with the range of temperatures encountered on a run is to choose whether to experience more discomfort by being colder for longer or warmer for longer. If the runner wears more clothes, he will not be as cold at the outset of the run and may not get as cold if he stops during the run, but he may be uncomfortably warm during the height of his physical exertion. Alternatively, if the runner chooses to wear fewer clothes, he will be colder at the outset of the run and if he stops during the run, but he may be more comfortable during the height of his physical exertion. Neither of these options is optimal because the runner still has to choose whether he would prefer to be uncomfortably cold or warm during a portion of his run.
An alternative way that the runner may balance the fluctuation in body temperatures during the duration of the workout is to dress in layers. As the runner's body temperature increases and decreases and the runner feels warmer and cooler, he may remove and add layers accordingly. However, this option requires a runner to carry articles of clothing that are not being worn. Additionally, this option requires a runner to change clothing during the workout. It may not be convenient or possible for a runner to carry multiple articles of clothing or have an opportunity to change clothes during the workout.
Another challenge associated with maintaining a comfortable body temperature while exercising in cold weather is managing sweat. If an athlete's body temperature is elevated too much by physical activity and multiple layers of clothing, the athlete's clothing becomes damp with sweat. The dampness makes the athlete feel colder as cold air passes over the wet fabric and transfers body heat away from the skin. One way to address damp clothing is by making the clothing out of materials which will dry quickly to prevent the loss of body heat. However, parts of the athlete's body may not be covered by articles of clothing made out of the drying material.
Another challenge associated with exercising outdoors in cold weather is maintaining comfort while breathing in cold, dry air. Humidity is a measurement of the amount of water vapor dissolved in air, and it varies as a function of both pressure and temperature. At a given pressure, the saturation temperature of water is the temperature at which water reaches an equilibrium between a liquid and a gas. When the temperature of the air is higher, the temperature of the water in the air is closer to the saturation temperature, more of the water is held in the air in vapor form and the air is more humid. When the temperature of the air is lower, the temperature of the water in the air is farther from the saturation temperature, more of the water is in liquid form and cannot be held in the air, so the air is less humid. Breathing in the cold, dry air can be uncomfortable and may result in dry coughing or even nosebleeds as the athlete's airways dry out.
One way to address breathing in cold air is by covering the nose or mouth of the athlete with fabric. As the athlete exhales, he expels heat and moisture from his lungs. The fabric captures a portion of heat and moisture expelled and retains it in the vicinity of the airways of the athlete so that when the athlete inhales, the cold and dry outside air mixes with the heat and moisture before it enters the athlete's airways. While articles of clothing exist which cover the nose or mouth, these may retain too much heat and moisture, becoming uncomfortably hot and humid. Alternatively, these articles may leave some portion of the neck exposed to the cold air, reducing the comfort of the athlete.
There is a need, therefore, for an improved garment that addresses issues associated with participating in athletic activities outdoors in cold weather. In view of the foregoing, it would be advantageous to provide an improved garment which allows an athlete to maintain a comfortable body temperature. It would be further advantageous if this garment manages sweat. It would also be advantageous if this garment allows the athlete to maintain comfort while breathing in cold air.